This invention relates to a disc brake for a vehicle, particularly to a disc and pads made of carbon fiber-reinforced carbon composites (hereinafter referred to as C/C composites) having excellent frictional properties.
In the disc brakes for vehicles, C/C composites are recently utilized for the disc which rotates integrally with the wheels and for the pads which are brought into frictional engagement with the disc from the standpoint of weight reduction and improvement of performance.
However, the disc and pads made of such C/C composites are susceptible to changes in the coefficient of friction depending on the temperature and cannot give a stable braking effect: the coefficient of friction is low in the low temperature range at the initial stage of braking operation but is gradually or rapidly elevated with the rise of temperature caused by the friction as the braking operation proceeds, or the low coefficient of friction remains as such.